I picked up a vibration at about 4800 rpm and it increased right through to the red line. I searched the bike for loose stuff but found nothing. Eventually looked at the motor mounts and found the culprits. I made a repair and so far it works like a charm and only cost me $10.30 to do four mounts. Video.....

This is the finished product.
The two bushings with flutes cut in are generic "stabilizer arm" bushings, common to many GM (and other) cars. Go to any automotive parts store and ask for a stabilizer arm kit. Unless you go to a very expensive foreign car dealership, all these kits will have the same bushings. I found the used ones were closer to the flexibilty of the ones I took out of the bike and are exactly 28mm. The new ones are stiffer and are 31 mm. But a quick roll on your bench grinder will take off as little as you need for them to fit snuggly.

The radiator hose was selected for both it's thickness and it's resistance to heat. I figured that some heat would be transfered from the pipes and block , thru the cup washer. So the radiator hose washer is to protect the more flexible roof vent washers. They were selected because of the flexibility, you could use three and it would still work and fit in the brackets no problem at all. I felt the greater flexibility would absorb the vibration better and it does. Dramatically. Come to think of it, next set I do will have three of the roof vent washers in them.